The aim of this case study was to explore the relationship between porphyrins and colon adenocarcinoma, and to examine the potential of porphyrin-induced fluorescence for the diagnosis of colon cancer. Further studies were carried on 8 cases ex vivo colon adenocarcinoma samples which exceptionally exhibited 635 nm fluorescence emission under 405 nm excitation. The time-resolved fluorescence spectra at 635 nm emission under 405 nm excitation were also measured and two-exponential decay fitting was performed to determine the fluorescence lifetime at 635 nm emission. Significant difference was observed between the spectra of normal and cancer tissues, which included an emission peak at 635 nm under the excitation wavelengths of 405 nm. There was also a significant difference between the fluorescence lifetimes of 635 nm emission of the normal tissue and cancer tissue (P<0.05). These results demonstrate that the spectroscopic analysis method allows a selective detection of adenocarcinoma tissues. This spectral profile and lifetime of the red fluorescence resemble that of porphyrins, which suggests that porphyrin fluorescence may be a useful biomarker for characterizing colon cancers of certain patient populations.
This study evaluates the potential of a discriminant analysis to classify colonic mucosa from
autofluorescence spectral characteristics. With 337 nm excitation, the autofluorescence spectra of colonic
tissues were measured using a FLS920 spectrofluorimeter. Principal component analysis (PCA) combined
with Fisher's discriminant analysis was performed for tissue classification. As a result, the sensitivity and
specificity of the discriminant analysis is 92.3% and 90.5%, respectively. The results suggest the relative
concentrations of collagen and nicotinamide adenine dinucleotide (NADH) are the potential diagnostic
biomarkers for colonic tissue classification using autofluorescence spectroscopy, and the discriminant
analysis based on PCA is useful to differentiate adenocarcinoma from normal tissue.
A laser induced fluorescence imaging system for localization of Nasopharyngeal Carcinoma is developed. In this
fluorescence imaging system, the fluorescence intensity with information of detected objection is gained by an image
intensifier, which makes color information of the fluorescence image eliminated and the result is a monochrome image of
the fluorescence with thermally induced noise. The monochrome fluorescence image is sent to a CCD and captured by an
image board, which is controlled by a computer. Image processing is carried out to improve the image quality and
therefore improve the system's ability to differentiate carcinomas from normal tissue. Gaussian smoothing is
implemented in order to reduce the noise. Image binarizing process is realized to obtain an optimal threshold of the
image. Image pixels with grey value below this threshold are assigned as diseased and those above are normal. A pseudo
color processing is then accomplished to get better visual perception and understanding of the image, greatly increasing
the detail resolution of the grey image. The processed image is then displayed on the screen of the computer in real time.
The real time laser induced fluorescence imaging system with the image processing methods developed is efficient for
localization of the nasopharyngeal carcinoma.
A novel wavelength detection and demodulation technique of fiber Bragg gratings sensors is put forward. The principle, experimental setup and results of the sensor are analyzed. The new technique converts detections of shift of center reflecting wavelength into detection of light intensity extremum. Furthermore, a spatial division multiplexing system of Bragg gratings sensors based on the novel technique is developed. The multiplexing numbers are not confined by bandwidth of light source and tunable scope of single fiber Bragg grating.
Both Raman and infrared spectrum measure vibrational transitions in molecules, so they can detect structure and clinical medical character of material in molecule level. Since human blood keeps in close touch with tissue, it may have some symptoms in the blood when functional disorder happens. For this reason, people have already developed a lot of methods to investigate the feasibility of using it to diagnose and therapy, especially in the orientation of non-invasive measurement. In this paper the principles of two kinds of spectra were analyzed and discussed first, involving the advantages and disadvantages in actual research. Then, according to different composition and research direction of human blood, we introduced the research progress of this field at present. Finally the difficulty we met and the expectation in the future are discussed.
Fourier transform in-infrared and near-infrared Raman spectroscopies were used to study human red cell. The assignment of characteristic groups of human red cell structure was basically confirmed. The intensity of different Raman shift signal has different varying law when the power of laser is changing and it doesn’t satisfy the simple linearity. Laser Raman spectroscopy combining with infrared spectroscopy is an effective method to study the structure of human red cell.
The therapeutic effectiveness of laser-electromagnetism combined therapy in chronic prostatitis is studied. Four patients were treated by irradiating the prostate’s correlative parts and acupoints with 650nm semiconductor laser and pulse electromagnetism respectively. Three of them were recovery and only one was ineffective. This demonstrates the feasibility of using laser-combined electromagnetism for assistant treatment on chronic prostatitis. A further study on combined therapy of chronic prostatitis using 810nm, 650nm semiconductor laser and pulse electromagnetic wave is also introduced.
The theoretical spectral response formula of the PIN Gallium phosphorus photodetector is given. At the same time, considering the process requirements, the optimum device structure parameters of GaP photodetector are obtained by numerical calculation and simulation. Under the condition of these structure parameters, the responsivity of the GaP photodetector will be obtained at a given wavelength.